White House chief of staff John Kelly spoke to the “good” and “not so good” parts of US history on Monday, speaking highly of Confederate general Robert E. Lee and attributing the origin of the American Civil War to a “lack of an ability to compromise.”

Kelly described history as “evolving,” and said it is “dangerous” to not be cognizant of it, when asked about the removal of historical but controversial statues commemorating Confederate figures during an interview on Fox News’ “The Ingraham Angle.”

“There will be, 100 or 200 years from now, people that criticize us for what we do, and I guess they’ll tear down, you know, statues of people that we revere today,” Kelly told Laura Ingraham. “It’s dangerous, I think. … It’s just very, very dangerous and it shows you what, how much of a lack of appreciation of history and what history is.”

The White House chief of staff called Lee “an honorable man” who chose duty to his state over loyalty to a federal government.

“It was always loyalty to state first back in those days,” Kelly said. “Now, it’s different today.”

He continued: “But the lack of an ability to compromise led to the Civil War. And men and women of good faith on both sides made their stand where their conscience had to make their stand,” Kelly added, not making any mention of slavery — a major facet of the Southern economy and a key benchmark that separated northern and southern states when they chose sides in the Civil War.

Racial tensions in the United States have been heightened in recent months after a group of white supremacists took to the streets in Charlottesville, Virginia, to protest the removal of a statute of Lee. One woman died when a man drove his car through a street filled with counterprotesters.

Trump has called the removal of the Confederate monuments “foolish.”

“Sad to see the history and culture of our great country being ripped apart with the removal of our beautiful statues and monuments,” Trump said in a series of tweets in August. “You can’t change history, but you can learn from it.”

Trump was criticized for his response to the incident, initially issuing a vague statement and saying the conflict was the fault of “many sides.” He later came out specifically against the “alt-right” and neo-Nazi groups, but then was criticized again when he said he thought there was blame on “both sides.”

Additionally, Trump has been at odds with players in the NFL who have protested against racism and police brutality during games by kneeling during the National Anthem. Trump has spoken out against the players both in person and repeatedly on Twitter, saying the gesture is disrespectful to the American flag.